Core plug

ABSTRACT

A core plug for mounting in the opposite ends of a tubular roll of material for rotatably supporting the roll about a spindle. The core comprises an annular, web-like, base portion which includes an axially-extended sleeve member defining a central opening adapted to receive the spindle member. A generally cylindrical rim integral with the base portion terminates in a radially-extending flange at the end of the rim opposite the base portion. A plurality of stiffening members are located intermediate two locations on the rim in such a manner that each of the stiffening members is tangent to the sleeve member and no stiffening member terminates at the sleeve member. Thus, forces tending to crush or deflect the rim will be transmitted to another portion of the rim without tending to crush or deflect the sleeve member. The characteristics of the location of the stiffening members are described in detail. The core plug also includes a plurality of axially-aligned rib members on the outer surface of the rim, each of which includes a plurality of protuberances thereon, the ribs and protuberances preventing the relative rotation of the core and the tubular roll of material.

United States Patent [191 Vetter Oct. 8, 1974 CORE PLUG Erich Vetter, Huntington, NY.

[73] Assignee: Uniflex, Inc., Westbury, NY.

[22] Filed: Mar. 9, 1972 [21] Appl. No.: 233,216

[75] Inventor:

[52] US. Cl. 242/68.6 [51] int. Cl. B6511 75/18 [58] Field of Search 242/68.5, 68.6, 118.61,

242/118.7; 206/59 R, 58, 59 C, 59 F;

Primary Examiner-George F. Mautz Assistant Examiner-John M. .lillions Attorney, Agent, or FirmLane, Aitken, Dunner & Ziems [57] ABSTRACT A core plug for mounting in the opposite ends of a tubular roll of material for rotatably supporting the roll about a spindle. The core comprises an annular, weblike, base portion which includes an axially-extended sleeve member defining a central opening adapted to receive the spindle member. A generally cylindrical rim integral with the base portion terminates in a radially-extending flange at the end of the rim opposite the base portion. A plurality of stiffening members are located intermediate two locations on the rim in such a manner that each of the stiffening members is tangent to the sleeve member and no stiffening member terminates at the sleeve member. Thus, forces tending to crush or deflect the rim will be transmitted to another portion of the rim without tending to crush or deflect the sleeve member. The characteristics of the location of the stiffening members are described in detail. The core plug also includes a plurality of axiallyaligned rib members on the outer surface of the rim, each of which includes a plurality of protuberances thereon, the ribs and protuberances preventing the relative rotation of the core and the tubular roll of material.

11 Claims, 6 Drawing Figures CORE PLUG BACKGROUND OF THE INVENTION This invention relates to a core plug for a tubular roll of material. More particularly, this invention relates to a core plug for mounting in the opposite ends of a roll of material for rotatably supporting the roll on a spindle. Still more particularly, this invention relates to a core plug made from a plastic material and including stiffening members so arranged that forces tending to collapse the rim of the core plug do not materially effeet the configuration of the central sleeve member adapted to receive the spindle.

It has long been known in the art to provide continuous sheets of material, such as paper, polyethylene, and the like, in the form of tubular rolls having a central core member. For use in connection with such rolls, the art has produced a number of core plugs for such rolls which are engaged and retained in the roll to protect the end of the material from damage, to prevent the core member from collapse, and to rotatably mount the roll on a spindle. In general, it is an aim in the development of core plugs to produce a plug which is strong and rigid and adapted for a wide range in diameters of cores, while producing a structure which may be securely engaged and retained in the core of the roll under severe handling. Examples of such core plugs known to the art are shown in the U.S. Pat. Nos. 1,919,769, issued July 25, 1933; 2,045,035, issued June 23, 1936; 2,269,939, issued Jan. 13, 1942; 3,567,146, issued Mar. 2, 1971; and 3,615,036 issued Oct. 26, 1971, as well as in patent Nos. 1,670,454, issued May 22, 1928; 1,861,294, issued May 31, 1932; and 1,908,108, issued May 9, 1933.

In addition to the number of functional characteristics disclosed by these patents, a wide'variety of designs for core plugs have been produced, as are evidenced by the design Pat. Nos. 222,634, 222,635, and 222,636, all issued Nov. 3, 1971, and in design patent No. 222,661, issued Nov. 30, 1971. 1

However, it is a continuing problem in the art to pro-= duce core plugs which are strong and relatively rigid. In particular, when utilizing a thermoplastic material such as polyethylene for the manufacture of suchplugs, it is a problem in the art to produce a satisfactory stiffening arrangement to prevent collapse of the rim of the core plug, as well as of the central sleeve member to insure long life for the core plug. Accordingly, a number of core plugs known to the art, including the plugs shown and described in the above-mentioned patents, have generally taken two approaches in an attempt to achieve a satisfactory solution to this problem. First, a number of designs are known in which the base portion of the plug is circumferentially corrugated or in which the rim of the plug utilizes a suitable stiffening technique. However, such solutions have beendeficient in that the outer rim of the core plug may be collapsed upon the application of severe forces. On the other hand, a number of designs have utilized axiallyextending stiffening members between the central sleeve members and the outer rim of the core plug to enhance the stability of the core plug. However, such solutions have not been entirely satisfactory since forces which tend to collapse the outer rim are transmitted through such axially-extending members to the sleeve member so that if the outer rim is collapsed 2 slightly the central sleeve member also tends to be collapsed. Accordingly, it is a principal object of this invention to provide a core plug of the type described which includes stiffening members arranged to transmit forces from the rim tending to collapse therim to another point on the rim without tending to collapse the sleeve member.

It is an additional aim in producing core plugs to provide ribs on the rims of the plug to grip rigidly the internal diameter of the core of the roll to prevent relative movement of the core plug and the core of the roll, thus to compensate for situations in which the core plug does not enjoy a substantially secure fit within the core. Such rib, portions are described in United States Pat. No. 1,919,769, mentioned above. In addition, a-core plug is known to the art which utilizes a plurality of protuberances on the rib portions, apparently for enhancing the gripping capability of the core plug within the core of the roll.

Accordingly, it is an object of this invention to provide a core plug of the type described, preferably made from a thermoplastic material, which achieves the aims described above while overcoming the problems in the art. r

It is an additional object of this invention to provide a core plug utilizing a plurality of stiffening members in such a manner that forces tending to collapse the rim portion of the core plug do not tend to collapse the central sleeve portion thereof.

It is an additional object of this invention to provide a thermoplastic core plug which utilizes a plurality of axially-extending ribs on the rim portion of the core plug, each of the ribs having a plurality of protuberances thereon. 1

These and other objects of the invention will become apparent from a review of the accompanying drawings, taken in conjunction with the written description of the invention.

BRIEF SUMMARY OF THE INVENTION v Directed to overcoming the problems of the prior art andachieving the aforestated objects, the core plug of the invention is adapted to be mounted on the opposite ends of a'roll of material, such as paper or polyethylene, for rotatably supporting the roll about a spindle member. The core plug comprises an annular, weblike, base portion which includes an axially-extended sleeve member defining a central opening about an axis. The sleeve member is adapted to rotatably receive the spindle member and is integrally formed with the web-like portion. A generally cylindrical rim is integral with the base portion and terminates in a radiallyextending flange at the end of the rim opposite the base portion. A plurality of stiffening members are located intermediate two respective locations on the rim in such a manner that each of the stiffening members is tangent to the sleeve member at a location thereon. The location of the stiffening member is further characterized in that no stiffening member terminates atthe sleeve member. In a preferred embodiment, each of the stiffening members has a surface defined by the length of a chord and a predetermined varying width and lies substantially on a tangent to the outer surface of the sleeve member. As particularly disclosed, the stiffening members are arranged in pairs separated by a distance I about equal to the outer diameter of the sleeve member so that each of a pair of the stifiening members lies substantially on diametrically opposed and parallel tangents to the outer surface of the sleeve member. The core plug further includes a plurality of axially-aligned rib members on the outer surface of the rim, each including a plurality of protuberances thereon, for nonrotatably securing the core plug relative to the core of the roll.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. I is a perspective view of the exterior of the core plug according to the invention about a spindle shown in phantom outline, and further illustrating the axiallyextending rib member and the plurality of protuberances thereon;

FIG. 2 is a plan view of the base portion of the core plug of FIG. 1;

FIG. 3 is a frontal plan view of the core plug of FIG. 1 showing the stiffening members relative to the central sleeve member and the radially-extending annular flange on the core plug;

FIG. 4 is a side view, partially in section, of the core plug engaged with the core of the roll of material wherein the combination of the core and roll is rotatably secured about a spindle;

FIG. 5 is a cross sectional view taken along line 5-5 of FIG. 3; and

FIG. 6 is a perspective view of a roll of material illustrating the core plug secured in one end thereof and a spindle rotatably secured in the sleeve member of the core plug.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the core plug according to the invention, designated generally by the reference numeral 10, is adapted for mounting in the opposite ends of a roll of material, such as paper, polyethylene, and the like, designated generally by the reference numeral 11. For example, the roll 11 may comprise a plurality of layers of such material 12 continuously wrapped about a core member 13, as best seen in FIG. 4. The core plug is adapted to be non-rotatably secured in the core member 13 in such a manner that the combination of the roll 11 and the core plug 10 is rotatable about a spindle member 14.

The core plug 10 comprises an annular, web-like, base portion 16 which includes an axially-extending sleeve member 17 which defines a central opening in the core plug III. The central opening is adapted to rotatably receive the spindle member I4. Preferably, the sleeve member 17 is generally cylindrical about an axis, designated generally by the reference numeral 18, so that the sleeve member is generally annular in cross section in which the difference between the inner radius of the cross section of the sleeve member and the outer radius of the sleeve member is determined by the wall thickness of the sleeve member 17. Preferably, the sleeve member 17 is integrally formed, such as during molding, with the web-like base portion 16.

A generally cylindrical outer rim is formed integrally with the annular web-like base 16. The rim 20 is generally cylindrical about the axis 18 and is preferably provided with a slight taper so that the outer radius of the rim 20 increases slightly with the increase in distance from the base portion 16. This tapering characteristic facilitates the insertion of the core plug 10 into the core member 13 of the roll 11. The cross section of the rim 20 is generally annular wherein the difference between the inner radius and the outer radius of the annulus of the rim is defined by the wall thickness of the rim 20. The rim 20 terminates in an axially-extending, annular flange 22 located on the end of the rim 20 opposite the web-like base portion 16. The radial thickness of the annular flange 22 may vary from a thickness sufficient to prevent overinsertion of the plug 10 into the core member 13, as shown in FIG. 4, and a somewhat larger radius which has the advantage of protecting the ends of the material 12 from being crushed.

A plurality of axially-aligned ribs 23 are integrally formed about the outer periphery of the rim 20. The outer surfaces of the ribs 23 lie substantially along the surface of a cylinder having its center'at the axis 18. Thus, since the rim 20 may taper inwardly slightly, as previously described, the apparent thickness of the rib 23 increases relatively near. the base portion 16 of the core plug 10, as best seen in FIGS. 1 and 4.

A plurality of protuberances 24 are located on the outer surface of each of the ribs 23 to enhance securing the core plug 10 in a non-rotatable relationship with the core member 13 of the roll 11. When such core members 13 are made from paper or other scorable material, the insertion of the core plug therein effectively scores the inner diameter of the core member 13 to effectively spline the core plug 10 in the core memberl3. The rib construction also permits the core plug to be used in core members having slight variation in their inner diameter since the ribs and protuberances imbed themselves in the inner diameter of the core member 13 to effectively hold the core plug against relative rotation even when the rim 20 does not fit closely within the core member 13. The ribs 23 and the protuberances 24 are preferably integrally formed on the rim 20.

As shown in FIGS. 3 and 5, a plurality of stiffening members, designated generally by the reference numeral 26, are located intermediate two respective locations on the rim 20 in such a manner that each of the stiffening members is tangent to the outer surface of the sleeve member 17 at a location thereon. The location of the stiffening members 26 in the core plug 10 of the invention is further characterized in that no stiffening member terminates at the sleeve member. The advantage of such construction is that forces applied to the rim 20 tend to be transmitted through the stiffening members to another portion of the rim 20 for absorption thereby without tending to collapse the sleeve member 17. This is a substantial advantage over stiffening members known to the prior art.

In a preferred embodiment, each of the stiffening members has a surface defined at its maximum extent by the length of a chord and a predetermined varying width, which width may vary from its maximum extent at therim 20 and its minimum extent adjacent the sleeve member 17. This variation in width of each of the stiffening members 26 is best seen by the line 28 in FIG. 5. Thus, the width of the stiffening member at about the sleeve member 17 is approximately the same as the axial length of the sleeve member 17, both taken relative to the base portion 16.

As best seen in FIG. 3, the stiffening members 26 are arranged in pairs separated by a distance approximately equal to the outer diameter of the sleeve member 17. Thus, each of a pairof the stiffening members 26 lies substantially on a tangent to the outer surface of the sleeve member 17 and the respective tangents are substantially parallel to one another.

In the preferred embodiment, four pairs of stiffening members are utilized. The first pair, designated generally by the reference numeral 31, is substantially vertically oriented and comprises a left member 32 and a right member 33. The second pair, designated generally by the reference numeral 35, comprises an upper member 36 and a lower member 37. The third pair, designated generally by the reference numeral 39, lies at an angle sloping upwardly to the right and comprises a left member 40 and a right member 41. The fourth pair of stiffening members, designated generally by the reference numeral 43, lies at an angle sloping upwardly to the left and comprises a left member 44 and a right member 45. As may be seen in FIG. 3, the terminal portion of each of the stiffening members terminates substantially equally spaced along the rim portion 20. For convenience, the terminal portions have been designated by the reference numerals 50-57.

The locations of the stiffening members are thus characterized as follows. The left member 44 of the fourth pair 43 is substantially coterminous at one end at point 57 with one end of the upper member 36 of the second pair 35 and at the other end with one end of the right member 33 of the first pair 31 at point 54. The right member 45 of the fourth pair 43 is substantially coterminous at point 50 at one end with one end of the left member 32 of the first pair 31 and at the other end at point.53 with the lower member 37 of the second pair 35. The left member 40 of the third pair 39 is coterminous at one end with the other end of the lower member 37 of the second pair at point 56 and at the other end with the other end of the right member 33 at location 5]. The right member 41 of the third pair 39 is coterminous at one end with the other end of the left member 32 of the first pair 31 at point 55 and at the other end with the upper member 36 of the second pair 35 at location 52. All of the coterminal locations 50-57 lie substantially on the rim 20.

In FIG. 5, the cross-sectional surface designated by the reference numeral 60 represents the inner section of stiffening members 40 and 45, while the cross sectional surface 61 represents the inner section between the surfaces 41 and 44.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed is:

l. A core plug for a tubular roll of material having an inner core diameter comprising:

an annular base portion which includes an axiallyextending sleeve member defining a central opening in said base portion and adapted to receive a spindle member for rotatably supporting said core plug and said roll about an axis, said sleeve member being integral with said base portion and generally cylindrical about said axis;

a rim integral with said base portion at the radially outermost portion thereof, said rim being generally cylindrical about the axis and having an axial length; and I a plurality of stiffening members each having a width in the direction of said axis which is equal to or less than the axial length of said rim, said plurality of stiffening members extending substantially linearly between two spaced-apart locations on said rim so that each of said stiffening members is tangent to and in contact with said sleeve member at a location thereon, at least one surface of each of said stiffening members being at least in part substantially planar and wherein each end of each of said stiffening members terminates at said rim and whereby forces tending to collapse said rim are resisted by said stiffening members in such a manner that said forces do not tend to collapse said sleeve member.

2. The core plug as defined in claim 1 wherein said rim terminates in a radially-extending flange at the end of said rim opposite said base portion.

3. The core plug as set forth in claim 1 wherein said one surface of each of said stiffening members is substantially parallel to said axis.

4. The core plug as set forth in claim 3 wherein the stiffening members are arranged in pairs separated by a distance about equal to the outer diameter of the sleeve member so that each of a pair of said stiffening members lies substantially on a tangent to the outer surface of said sleeve member.

5. The core plug as set forth in claim 4 wherein the portions of said stiffening members which terminate on said rim terminate substantially equally spaced along said rim portion.

6. The core plug as set forth in claim 5 wherein the portion of one of a pair of stiffening members which terminates on said rim is substantially coterminous with the portion of one of another pair of stiffening members which terminates on said rim.

7. The core, plug as defined in claim 4 wherein the pairs of stiffening members are arranged so that, in a plan view of said core plug, when a first pair lies substantially vertically, a second pair lies substantially horizontally, a third pair lies at an angle sloping upwardly to the left and a fourth pair lies at an angle sloping upwardly to the right.

8. The core plug as set forth in claim 7 wherein the locations of the stiffening members are further characterized when seen in said plan view as follows:

the left member of said fourth pair is substantially coterminous at one end with one end of the upper member of said second pair and at the other end with one end of the right member of said first pair;

the right member of said fourth pair is substantially coterminous at one end with one end of the left member of said first pair and at the other end with the lower member of said second pair;

the left member of the third pair is coterminous at one end with the other end of the lower member of said second pair and at the other end with the other end of the right member of said first pair;

said right member of said third pair is coterminous at one end with the other end of the upper member of said second pair and at the other end with the other end of the left member of said first pair; and

all of said coterminous locations lying substantially at said rim.

9. The core plug as set forth in claim 1 wherein said rim is slightly inwardly tapered so that the narrowest eluding a plurality of axially-aligned rib members on the outer surface of said rim.

11. The core plug as set forth in claim 10 further inportion of said rim is substantially adjacent said base 5 eluding a plurality of pmtuberances on each of said rib portion.

10. The core plug as set forth in claim 1 further inmembers' 

1. A core plug for a tubular roll of material having an inner core diameter comprising: an annular base portion which includes an axially-extending sleeve member defining a central opening in said base portion and adapted to receive a spindle member for rotatably supporting said core plug and said roll about an axis, said sleeve member being integral with said base portion and generally cylindrical about said axis; a rim integral with said base portion at the radially outermost portion thereof, said rim being generally cylindrical about the axis and having an axial length; and a plurality of stiffening members each having a width in the direction of said axis which is equal to or less than the axial length of said rim, said plurality of stiffening members extending substantially linearly between two spaced-apart locations on said rim so that each of said stiffening members is tangent to and in contact with said sleeve member at a location thereon, at least one surface of each of said stiffening members being at least in part substantially planar and wherein each end of each of said stiffening members terminates at said rim and whereby forces tending to collapse said rim are resisted by said stiffening members in such a manner that said forces do not tend to collapse said sleeve member.
 2. The core plug as defined in claim 1 wherein said rim terminates in a radially-extending flange at the end of said rim opposite said base portion.
 3. The core plug as set forth in claim 1 wherein said one surface of each of said stiffening members is substantially parallel to said axis.
 4. The core plug as set forth in claim 3 wherein the stiffening members are arranged in pairs separated by a dIstance about equal to the outer diameter of the sleeve member so that each of a pair of said stiffening members lies substantially on a tangent to the outer surface of said sleeve member.
 5. The core plug as set forth in claim 4 wherein the portions of said stiffening members which terminate on said rim terminate substantially equally spaced along said rim portion.
 6. The core plug as set forth in claim 5 wherein the portion of one of a pair of stiffening members which terminates on said rim is substantially coterminous with the portion of one of another pair of stiffening members which terminates on said rim.
 7. The core plug as defined in claim 4 wherein the pairs of stiffening members are arranged so that, in a plan view of said core plug, when a first pair lies substantially vertically, a second pair lies substantially horizontally, a third pair lies at an angle sloping upwardly to the left and a fourth pair lies at an angle sloping upwardly to the right.
 8. The core plug as set forth in claim 7 wherein the locations of the stiffening members are further characterized when seen in said plan view as follows: the left member of said fourth pair is substantially coterminous at one end with one end of the upper member of said second pair and at the other end with one end of the right member of said first pair; the right member of said fourth pair is substantially coterminous at one end with one end of the left member of said first pair and at the other end with the lower member of said second pair; the left member of the third pair is coterminous at one end with the other end of the lower member of said second pair and at the other end with the other end of the right member of said first pair; said right member of said third pair is coterminous at one end with the other end of the upper member of said second pair and at the other end with the other end of the left member of said first pair; and all of said coterminous locations lying substantially at said rim.
 9. The core plug as set forth in claim 1 wherein said rim is slightly inwardly tapered so that the narrowest portion of said rim is substantially adjacent said base portion.
 10. The core plug as set forth in claim 1 further including a plurality of axially-aligned rib members on the outer surface of said rim.
 11. The core plug as set forth in claim 10 further including a plurality of protuberances on each of said rib members. 